Re: [volt-nuts] low emf solder

2016-10-31 Thread David
On Sat, 29 Oct 2016 20:41:48 +0200, you wrote: >On Sat, 29 Oct 2016 15:27:49 +0100 >"Dr. David Kirkby (Kirkby Microwave Ltd)" >wrote: > >> But if one could use copper as the bond wire, rather than gold which is >> quite common, then it would give you very little

Re: [volt-nuts] low emf solder

2016-10-31 Thread Florian Teply
Am Sat, 29 Oct 2016 20:41:48 +0200 schrieb Attila Kinali : > On Sat, 29 Oct 2016 15:27:49 +0100 > "Dr. David Kirkby (Kirkby Microwave Ltd)" > wrote: > > > But if one could use copper as the bond wire, rather than gold > > which is quite common,

Re: [volt-nuts] low emf solder

2016-10-31 Thread Florian Teply
Am Sun, 30 Oct 2016 01:05:56 -0500 schrieb David : > Sounds more like copper free copper than oxygen free copper. To be fair, one does not exclude the other. And nobody specified to what the 100% is supposed to apply to. Being oxygen free does not necessarily imply that it

Re: [volt-nuts] low emf solder

2016-10-31 Thread Andrea Baldoni
On Sat, Oct 29, 2016 at 03:27:49PM +0100, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > Perhaps the person who was making the measurements on the solder, could try > making a thermocouple by welding two bits of wire taken from different > sources. I guess the problem would be preventing any

Re: [volt-nuts] low emf solder

2016-10-30 Thread John Phillips
good one. On Sat, Oct 29, 2016 at 11:05 PM, David wrote: > Sounds more like copper free copper than oxygen free copper. > > On Sun, 30 Oct 2016 01:06:12 +, you wrote: > > >Once you get past 99.99% purity funny things begin to happen... I have > some 100% pure Cu

Re: [volt-nuts] low emf solder

2016-10-30 Thread David
Sounds more like copper free copper than oxygen free copper. On Sun, 30 Oct 2016 01:06:12 +, you wrote: >Once you get past 99.99% purity funny things begin to happen... I have some >100% pure Cu oxygen free cable (says so right on the jacket) made in China >that is magnetic! You can't do

Re: [volt-nuts] low emf solder

2016-10-29 Thread John Allen
Googling for "Things I Won't Work With" finds the article and others by Derek Lowe in his blog. John K1AE -Original Message- From: volt-nuts [mailto:volt-nuts-boun...@febo.com] On Behalf Of Mark Sims Sent: Saturday, October 29, 2016 1:38 AM To: volt-nuts@febo.com Subject: [volt-nuts]

Re: [volt-nuts] low emf solder

2016-10-29 Thread Attila Kinali
On Sat, 29 Oct 2016 15:27:49 +0100 "Dr. David Kirkby (Kirkby Microwave Ltd)" wrote: > But if one could use copper as the bond wire, rather than gold which is > quite common, then it would give you very little thermal EMF Copper is more and more used for bonding

Re: [volt-nuts] low emf solder

2016-10-29 Thread Dr. David Kirkby (Kirkby Microwave Ltd)
On 29 October 2016 at 14:51, NeonJohn wrote: > > > On 10/28/2016 08:39 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > > > I wonder how practical it is to weld test leads, so there's no solder or > > thermal EMF. > > > > I know that this will sound crazy, and probably

Re: [volt-nuts] low emf solder

2016-10-29 Thread NeonJohn
On 10/28/2016 08:39 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: > I wonder how practical it is to weld test leads, so there's no solder or > thermal EMF. > > I know that this will sound crazy, and probably is, but could one weld > components to a PCB? Yes indeed. About 20 years ago I

Re: [volt-nuts] low emf solder

2016-10-29 Thread NeonJohn
probably because they drowned some lab rats with solutions of the stuff. As we say in the health-physics business, "the devil's in the dose". If I were working in a cad plating outfit, yeah, I'd check into what is behind the IARC's somewhat arbitrary designation. Making a small batch of cad

Re: [volt-nuts] low emf solder

2016-10-28 Thread David
On Sat, 29 Oct 2016 01:39:12 +0100, you wrote: >On 28 Oct 2016 15:25, "Juris L" wrote: > >I wonder how practical it is to weld test leads, so there's no solder or >thermal EMF. > >I know that this will sound crazy, and probably is, but could one weld >components to a PCB? > >I

Re: [volt-nuts] low emf solder

2016-10-28 Thread Scott Stobbe
Typing on phone... If the bond wires are gold they still are dissimilar to pcb copper, but if they were copper bond wires, thermal gradients would be less of an issue. On Friday, 28 October 2016, Scott Stobbe wrote: > "chip on board", not sure that it wouldnt help > >

Re: [volt-nuts] low emf solder

2016-10-28 Thread Scott Stobbe
"chip on board", not sure that it wouldnt help On Friday, 28 October 2016, Dr. David Kirkby (Kirkby Microwave Ltd) < drkir...@kirkbymicrowave.co.uk> wrote: > On 28 Oct 2016 15:25, "Juris L" > wrote: > > > > Found reference to optimal emf solder composition

Re: [volt-nuts] low emf solder

2016-10-28 Thread Howard Davidson
I note that  I weld thermocouples.  hld Howard L. Davidson hl...@att.net From: Dr. David Kirkby (Kirkby Microwave Ltd) <drkir...@kirkbymicrowave.co.uk> To: Discussion of precise voltage measurement <volt-nuts@febo.com> Sent: Friday, October 28, 2016 5:39 PM Subject: Re

Re: [volt-nuts] low emf solder

2016-10-28 Thread Bruce Griffiths
Laser welding should work for either similar or dissimilar materials.At one time microwire PCBs  used stainless steel  wires were welded to stainless lands. Bruce  On Saturday, 29 October 2016 1:39 PM, Dr. David Kirkby (Kirkby Microwave Ltd) wrote: On

Re: [volt-nuts] low emf solder

2016-10-28 Thread Dr. David Kirkby (Kirkby Microwave Ltd)
On 28 Oct 2016 15:25, "Juris L" wrote: > > Found reference to optimal emf solder composition cadmium/tin alloy > (70 %/30 %) in JJ array measurement article page 12. I wonder how practical it is to weld test leads, so there's no solder or thermal EMF. I know that this will

Re: [volt-nuts] low emf solder

2016-10-28 Thread Poul-Henning Kamp
In message , NeonJohn writes: >Let's don't get carried away with cadmium toxicity. Yes, it is toxic is >sufficient dose but the LD50 dose for Cd is 750 mg/kg while the value >for lead is around 450mg/kg. Read how a professional

Re: [volt-nuts] low emf solder

2016-10-28 Thread Neville Michie
LD50 is not the only consideration. From Wikipedia: "The International Agency for Research on Cancer has classified cadmium and cadmium compounds as carcinogenic to humans." FWIW Neville Michie > On 29 Oct 2016, at 8:09 AM, NeonJohn wrote: > > Let's don't get carried

Re: [volt-nuts] low emf solder

2016-10-28 Thread NeonJohn
Let's don't get carried away with cadmium toxicity. Yes, it is toxic is sufficient dose but the LD50 dose for Cd is 750 mg/kg while the value for lead is around 450mg/kg. As far as dumping it in a solder pot, that works just fine for me. It's cheaper to buy 50/50 plumber's bar solder and then

Re: [volt-nuts] low emf solder

2016-10-28 Thread ed breya
I would recommend against trying to use cadmium - it's very toxic, which is why Cd-based solders are rare nowadays. They are probably still made, but for lab or industrial use with proper handling. If you try to alloy it with Sn yourself without proper handling, you could get poisoned. You